Field of the Disclosure
The present disclosure relates to an organic light emitting diode display device and a method of manufacturing the same, and more particularly, to an organic light emitting diode display device with enhanced light extraction efficiency.
Description of the Related Art
In general, an organic light emitting diode display device as a self-light emitting display device does not require a separate light source which is usually included in a liquid crystal display device such that the organic light emitting diode display device is thinly and lightly manufactured. Further, the organic light emitting diode display device is driven with low voltage and power consumption and excellent even in color expression, response speed, viewing angle, and contrast ratio (CR), and thus the organic light emitting diode display device has been researched as a next-generation display.
The light emitted from an organic emission layer of the organic light emitting diode display device passes through various constituent elements of the organic light emitting diode display device to travel to the outside. However, some of the light is trapped within the organic light emitting diode display device and does not travel to the outside; thus, there is a problem in light extraction efficiency of the organic light emitting diode display device.
Particularly, a total reflection or a light absorption occurs by an anode electrode in the organic light emitting diode display device having a bottom emission structure, and thus approximately 50% of the light emitted from the organic emission layer may be lost. Such a total reflection or a light absorption also occurs on the substrate and thus, approximately 30% of the light emitted from the organic emission layer may also be lost. As such, approximately 80% of the light emitted from the organic emission layer may be blocked in the organic light emitting diode display device and only approximately 20% of the light may travel to the outside, and thus the light efficiency is overly low.
In order to improve the light extraction efficiency of the organic light emitting diode display device, a method of attaching a micro lens array (MLA) on the outside substrate of the organic light emitting diode display device or forming a micro lens on an overcoating layer of the organic light emitting diode display device has been proposed.
However, in spite of introducing an MLA or a micro lens in the organic light emitting diode display device, the light blocked in organic light emitting diode display device may remain large and the light amount extracted to the outside may remain small. Further, a part of the light incident on the substrate may be reflected in the same state as a polarization axis of a polarizing plate by introducing an MLA or a micro lens. As a result, reflectivity of the organic light emitting diode display device may increase. Further, the light generated in the organic emission layer passes through the substrate to reach the polarizing plate and is reflected again in the polarizing plate, and thus a path of the light is converted in a substrate direction. Herein, a part of the light directed in the substrate direction may reach the micro lens of adjacent pixels emitting different colors of light to cause a light leakage phenomenon.